Blue. But better. The Bose S1 Pro Play-Through Cover in Baltic Blue is the perfect way to add a fresh new look to your S1 Pro. With a sleek fitted design, the cover fits snugly over your system and fastens at the rear with a high-quality zipper. Don't want to take it off? You don't have to. Thanks to the acoustically-transparent stretchable fabric construction, you still get that phenomenal Bose sound - as if the cover wasn't installed at all. Plus, handy cutouts on the rear mean you can still access all of your S1's connections and controls with ease. The perfect blend of form and function.